The "other" headaches: primary cough, exertion, sex, and primary stabbing headaches.

Primary cough headache, primary exertional headache, primary sexual headache, and idiopathic stabbing headache are included in "Other Primary Headaches" (Group 4) in the International Classification of Headache Disorders, 2nd edition (ICHD-II). Headaches provoked by cough, exertion, and sex have different age distributions, but they do share some clinical and pathogenic characteristics. The triggering activities frequently involve Valsalva-like maneuvers, which may explain part of the pathogenesis. Primary stabbing headache is common and characterized by ultra-short stabbing headaches. All these headache disorders respond well to indomethacin, and they are commonly comorbid with migraine except for primary cough headache. Of note, some patients with sexual headache had reversible cerebral vasoconstriction syndromes. Recent large-scaled studies have revealed that the ICHD-II criteria of these four headache disorders cannot be completely fulfilled. Further revisions for the ICHD-II criteria are required based on these results of the evidence-based studies.